What did you do yesterday? The polite past form
You know several complete verbs ending in ます from lesson 06. First say みずをのみます aloud. Then replace only the final ます with ました and put きのう first: that gives you the first sentence of this lesson.
1. From ます to ました
In this lesson, a polite verb ending in ます gets an affirmative past form by replacing the final ます with ました. のみます becomes のみました, たべます becomes たべました, and べんきょうします becomes べんきょうしました. The part before ます stays in place for these familiar verbs.
Use ました here for concrete events that took place in the selected past time frame. きのう (KINOU), ‘yesterday’, makes that time frame clear. ‘Completed’ describes the practice situations; do not treat ました as a separate word that always literally means ‘finished’. Do not add an extra です after the verb: のみました is already polite.
きのう、みずをのみました。
きのう、おにぎりをたべました。
2. Seven familiar actions in the past
Use activities you already know: drinking, eating, buying, taking a physical object, watching, reading, and studying. Repeat each pair: のみます／のみました, たべます／たべました, かいます／かいました, とります／とりました, みます／みました, よみます／よみました, and べんきょうします／べんきょうしました. When you hear ました at the end, the polite form is in the past.
As in lesson 06, とりました here means that someone picked up or took a physical object. Do not automatically interpret it as ‘taking a photo’; that other meaning needs additional context and vocabulary. テレビ can be the object of みました, while ほん fits よみました. Match by meaning, not just by a shared ending.
When reading, notice small ょ in べんきょうしました and the difference between よみました and よんでいます. In the past form, the よみ- base remains visible. Use the vocabulary round for recognition first, then return to make complete sentences.
きのう、テレビをみました。
きのう、ほんをよみました。
きのう、にほんごをべんきょうしました。
3. Ask about an event from yesterday
きのう、なにをしましたか (KINOU, NANI O SHIMASHITA KA) asks ‘What did you do yesterday?’. きのう sets the time frame, なに asks for the content of the action, を marks that content, and しましたか closes the polite past question. The word order remains ordinary Japanese word order; you do not move an auxiliary to the front as in some Dutch or English questions.
An answer may repeat きのう, but does not need to when the conversation is already clearly about yesterday. Give one or two concrete affirmative events. The negative past is not a target yet, and you do not need a question with どこで. Keep this bridge small: time, object, and a familiar positive verb ending in ました.
きのう、なにをしましたか。
ほんをよみました。
4. The same activity in three time frames
Compare one activity without mixing the forms. みずをのみます is non-past and can describe a habit or plan in a suitable context. いま、みずをのんでいます uses the fixed lesson 07 phrase for drinking in progress. きのう、みずをのみました places the drinking in the past. The time word helps, but the verb ending also carries meaning.
Choose the intended time frame first, then select the matching form. Do not write きのう、のみます when the task explicitly asks for a completed event yesterday. Also do not write ましたです: both parts would compete for the same politeness role, while ました is already the complete polite verb ending.
5. Describe two events
In a short conversation, one question can invite several events. Bram first says that he bought sparkling water and then adds that he ate a rice ball. Because きのう already appears in the question, he does not need to repeat the time word in every answer. Both verbs still end in ました, so the past time remains audible.
First read only the Japanese lines and mark the two objects and two verbs. Then play both roles. In a second round, replace sparkling water with television and choose the matching verb みました. The result is a new combination rather than a copy of the first answer.
きのう、なにをしましたか。
たんさんすいをかいました。
おにぎりをたべました。
6. Recall independently without new grammar
Write three familiar ます-forms in a column and change only their ending to ました. Then add a sensible object to each form. Read the three sentences with きのう aloud once. Check separately whether the object makes sense with the action and whether the verb truly ends in ました.
The final check first asks you to recognise meaning, then to produce two short sentences. Use kana, the corresponding kanji, or romaji. You do not need to say where an action happened or form a negative past.